// --------------------------------------------------------------------------------------------------------------------
// <copyright file="AsyncEventArgs.cs" company="Microsoft Corporation">
// The MIT License (MIT)
// 
// Copyright (c) 2014, Microsoft Corporation
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
// </copyright>
// --------------------------------------------------------------------------------------------------------------------
namespace Microsoft.Robotics.Hardware.DAC
{
    using System;

    /// <summary>
    /// Represents an async operation.
    /// </summary>
    public class AsyncEventArgs : EventArgs
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="AsyncEventArgs"/> class.
        /// </summary>
        /// <param name="transport">The transport.</param>
        /// <param name="buffer">The buffer.</param>
        /// <exception cref="ArgumentNullException">Transport is null, or buffer is null</exception>
        protected AsyncEventArgs(ITransport transport, byte[] buffer)
        {
            if (transport == null)
            {
                throw new ArgumentNullException("transport");
            }

            if (buffer == null)
            {
                throw new ArgumentNullException("buffer");
            }

            this.Transport = transport;
            this.Buffer = buffer;
            this.Offset = 0;
            this.Count = buffer.Length;
        }

        /// <summary>
        /// Occurs when the async operation completes.
        /// </summary>
        public event EventHandler<AsyncEventArgs> Completed;

        /// <summary>
        /// Gets the transport.
        /// </summary>
        public ITransport Transport { get; private set; }

        /// <summary>
        /// Gets the buffer.
        /// </summary>
        public byte[] Buffer { get; private set; }

        /// <summary>
        /// Gets or sets the offset.
        /// </summary>
        /// <value>
        /// The offset.
        /// </value>
        public int Offset { get; set; }

        /// <summary>
        /// Gets or sets the count.
        /// </summary>
        /// <value>
        /// The count.
        /// </value>
        public int Count { get; set; }

        /// <summary>
        /// Gets or sets the bytes transferred.
        /// </summary>
        /// <value>
        /// The bytes transferred.
        /// </value>
        public int BytesTransferred { get; set; }

        /// <summary>
        /// Gets or sets the type of the operation.
        /// </summary>
        /// <value>
        /// The type of the operation.
        /// </value>
        public AsyncOperation OperationType { get; set; }

        /// <summary>
        /// Gets or sets the last error.
        /// </summary>
        /// <value>
        /// The last error.
        /// </value>
        public Exception LastError { get; set; }

        /// <summary>
        /// Called when the async operation completes.
        /// </summary>
        protected virtual void OnCompleted()
        {
            EventHandler<AsyncEventArgs> completed = this.Completed;
            if (completed != null)
            {
                completed(this.Transport, this);
            }
        }
    }
}
